Internal leaks in gas operated liquid-pumping pumps result in the discharge of liquid into the atmosphere. When the liquids being pumped are environmentally unsafe, their discharge into the atmosphere may pose significant health risks. The problem of internal leaks is particularly evident with air operated diaphragm pumps. The compressed air driving a diaphragm pump is separated from the liquid being pumped by an elastomeric diaphragm. When a diaphragm failure (e.g., a tear or hole in the diaphragm) occurs, the liquid being pumped mixes with the air driving the pump. In essence, when the pump is on its inlet or suction stroke, the liquid gets sucked through the tear or hole of the failed diaphragm. The liquid contaminates the compressed air. After the pump power function is completed the contaminated air is exhausted to the atmosphere.
The present invention is an apparatus and a method for containing the liquid leaked, for detecting such leak, and for stopping the pump operation when such leak is detected. The present system is driven by the same compressed gas that drives the pump, requiring no other external power source. In essence, once connected to the pump system, a self-contained pump-leak preventer system is formed. While the prior art discloses a system for diaphragm pump leak detection and subsequent shutoff, none discloses the technique of the present invention. The prior art discloses systems that require the use of energy sources other than the gas used to drive the pump. For example, one disclosed system required the use of electricity and another the use of light. In addition, unlike the present invention, some prior art systems require special sensors such as optical sensors.